Structure of the H2O–(CO2)2 trimer

Abstract
Rotational constants reported previously [J. Chem. Phys. 9 0, 5964 (1989)] for the C2 asymmetric tops H2O–(CO2)2, D2O–(CO2)2, H218O–(CO2)2 and H2O–(13CO2)2 have been reanalyzed. It is found that the slipped parallel (CO2)2 subunit, instead of remaining planar as in the free dimer, has the inner oxygens rotated away from the H2O by ∼20°. This leads to C–C and c.m. (H2O) to c.m. (CO2)2 distances of 3.497 and 2.370 Å in the clusters.